Radiant in-floor heating is widely regarded as the most comfortable, healthiest and most natural heating process available. Thousands years ago ancient Romans discovered radiant in-floor heating by introducing hot air directly from a wood fired furnace into the chambers underneath the floor. The crude wood fired in-floor systems developed by ancient Romans are no longer used because they are inefficient and unsafe.
The modern popular radiant in-floor heating systems utilise hot fluids circulating through the tubes (hydronic systems) or electric current through cables (electrical resistance systems) installed in concrete slabs or attached to the subfloor and covered with a pourable gypsum floor underlayment. Hot fluids circulating through the tubes or electrical resistance in the cables warm the underlayment and the floor covering above. The floors never become hot, just pleasantly warm. Hydronic and electrical resistance systems, however, have the disadvantages of high capital and installation costs, potential construction delays resulting from the co-ordination of specialty subcontractors and the difficulty and high cost involved in maintenance and repair. Consequently, such systems have not flourished in the residential housing market.
It is difficult to find any radiant in-floor heating systems in the present market that use hot air as the heating medium. Further, the prior arts of in-floor radiant heating systems based on heated air suffer from inefficiencies in absorbing heat from hot air and distributing heat uniformly across the entire floor surface.
The present invention relates in general to a radiant in-floor heating system using heated air as an energy source circulating inside of a sealed floor system. Specifically, the present invention relates to a radiant in-floor heating system built into a structural floor system that is specifically constructed using metal joists and a radiant metal sheet.